/**
 * Provides suggestions for state names (USA).
 * @class
 * @scope public
 */
function RemoteCitiesuggestions() {

  if (typeof XMLHttpRequest != "undefined") {
    this.http = new XMLHttpRequest();
  } else if (typeof ActiveXObject != "undefined") {
    this.http = new ActiveXObject("MSXML2.XmlHttp");
  } else {
    alert("No XMLHttpRequest object available. This functionality will not work.");
  }

}

/**
 * Request suggestions for the given autosuggest control. 
 * @scope protected
 * @param oAutoSuggestControl The autosuggest control to provide suggestions for.
 */
RemoteCitiesuggestions.prototype.requestSuggestions = function (oAutoSuggestControl /*:AutoSuggestControl*/,
                                                          bTypeAhead /*:boolean*/) {
  var oHttp = this.http;
                                                           
  //if there is already a live request, cancel it
  if (oHttp.readyState != 0) {
    oHttp.abort();
  }                 
  
  //build the URL
  var sURL = "/php/city-suggestions.php?userInput=" + encodeURIComponent(oAutoSuggestControl.textbox.value);
  
  //open connection to cities list file
  oHttp.open("get", sURL , true);
  oHttp.onreadystatechange = function () {
    if (oHttp.readyState == 4) {
      //evaluate the returned text JavaScript (an array)
      var aSuggestions = eval(oHttp.responseText);
  
      //provide suggestions to the control
      oAutoSuggestControl.autosuggest(aSuggestions, bTypeAhead);        
    }    
  };
  oHttp.send(null);
};